Heat-generating fabric and textile product

ABSTRACT

A heat-generating fabric contains an modacrylic fiber A and an animal hair fiber. The modacrylic fiber A contains an infrared absorber inside of the fiber, in an amount of 1 to 30% by weight with respect to the total weight of the modacrylic fiber, and the fabric has a heat-shielding rate of less than 40% as measured according to JIS L 1951:2019. The heat-generating fabric contains a first yarn and a second yarn whose fiber composition is different from that of the first yarn. The first yarn may contain the modacrylic fiber A, and the second yarn may contain the animal hair fiber. Accordingly, it is possible to provide a fabric with good heat-generating performance and durability, and a textile product containing the fabric.

TECHNICAL FIELD

One or more embodiments of the present invention relate to a heat-generating fabric containing an modacrylic fiber and having heat-generating properties, and a textile product containing the same.

BACKGROUND

For the purpose of heat retention in a cold environment, for example, clothing is worn. Recently, textile products and the like have been developed that are intended to make the temperature environment inside clothing comfortable by actively generating and storing heat in the textile fabric that constitutes the clothing. For example, Patent Document 1 describes that a heat-retaining textile fabric containing an infrared absorber and hollow particles has been developed. In this fabric, the infrared absorber generates heat when irradiated with infrared rays, and the hollow particles form dead air to reduce heat loss due to air convection. Accordingly, the fabric can store heat generated by the infrared absorber, resulting in the realization of a fabric with heat-retaining properties.

Patent Document

-   Patent Document 1: Japanese Patent No. 3305249

However, according to the heat-retaining textile fabric described in Patent Document 1, although heat loss can be reduced by the hollow particles, when the hollow particles are kneaded into the fiber, the fiber whitens and becomes opaque due to the difference in refractive index between void portions of the hollow particles and resin portions, causing a problem in the color development properties. Moreover, in the method of applying the infrared absorber and the hollow particles on the fabric surface, the feel and texture of the fabric surface are impaired, and, furthermore, the infrared absorber and the hollow particles are detached from the fabric surface as the frequency of use, washing, and the like increases, causing poor durability.

In order to solve the above, one or more embodiments of the present invention provides a heat-generating fabric with good heat-generating performance and durability, and a textile product containing the same.

SUMMARY

One or more embodiments of the present invention relate to a heat-generating fabric containing an modacrylic fiber A and an animal hair fiber, wherein the modacrylic fiber A contains an infrared absorber inside the fiber, in an amount of 1 to 30% by weight with respect to a total weight of the modacrylic fiber, and the fabric has a heat-shielding rate of less than 40% as measured according to JIS L 19512019.

Furthermore, one or more embodiments of the present invention relate to a textile product containing the heat-generating fabric described above.

According to one or more embodiments of the present invention, it is possible to provide a heat-generating fabric with excellent heat-generating performance and durability, and a textile product containing the same.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present inventors conducted an in-depth study in order to address the above. As a result, it was found that, if modacrylic fibers A containing a specific amount of infrared absorber inside the fibers and animal hair fibers are used in combination, the heat-shielding rate of the fabric is less than 40%, and thus one or more embodiments of the present invention were arrived at. It seems that the infrared absorber contained in modacrylic fibers A absorbs infrared rays and converts them into heat, and the heat-insulating effect of the animal hair increases the amount of heat generated, resulting in a somewhat larger temperature rise. Furthermore, there is a correlation between the amount of heat generated and the heat-shielding rate. The larger the amount of heat generated, the lower the heat-shielding rate, and, when the heat-shielding rate is less than 40%, the human body feels warm.

Furthermore, since the infrared absorber is contained inside the modacrylic fibers, the durability against washing and the like becomes good.

Furthermore, since the fabric contains modacrylic fibers, which can be dyed, the color development properties become good, and the range of application as textile products is widened.

Furthermore, since modacrylic fibers have a wool-like touch, the touch is not impaired, and, moreover, since modacrylic fibers have heat-retaining properties, the range of application as heat-generating textile products may be widened.

Heat-Shielding Rate

The heat-shielding rate is a value as measured based on Japanese Industrial Standards JIS L 19512019 “Textiles-Determination of heat-ray shielding performance”, which is a ratio obtained by dividing, by the temperature rise in a heat ray receiver in a blank test, a difference between the temperature rise in the heat ray receiver to which a test piece of fabric that is to be evaluated is attached and the temperature rise in the heat ray receiver in the blank test. The lower the heat-shielding rate, the higher the heat-generating performance, and, the higher the heat-shielding rate, the lower the heat-generating performance.

In one or more embodiments of the present invention, the heat-shielding rate of the heat-generating fabric is less than 40%, that is, the heat-generating performance is good. From the viewpoint of heat-generating performance, the heat-shielding rate may be less than 35%. If the heat-shielding rate is 40% or more, the heat-generating performance is low. Note that, from the viewpoint of heat-generating performance, the lower the heat-shielding rate of the heat-generating fabric, the better. There is no particular limitation on the lower limit thereof, and it may be 5% or more.

If the front face and the back face of the heat-generating fabric have different exposed ratios of modacrylic fibers containing an infrared absorber, the heat-shielding rate is measured such that a face with a higher exposed ratio of modacrylic fibers containing an infrared absorber is set as an irradiation face. If the front face and the back face of fabric have the same exposed ratio of modacrylic fibers containing an infrared absorber, the irradiation face may be either the front face or the back face.

Modacrylic Fibers a

The modacrylic fibers A contain 1 to 30% by weight of infrared absorber with respect to the total weight of the modacrylic fibers A. Accordingly, the modacrylic fibers A have a high infrared absorbency, and can produce a fabric with a heat-shielding rate of less than 40% when used in combination with animal hair fibers. From the viewpoint of improving the infrared absorbency, the infrared absorber may be contained in an amount of 2% by weight or more, 2.5% by weight or more, 3% by weight or more, or 3.5% by weight or more, with respect to the total weight of the modacrylic fibers A. From the viewpoint of spinnability, the infrared absorber may be contained in an amount of 20% by weight or less, 15% by weight or less, or 10% by weight or less, with respect to the total weight of the modacrylic fibers A.

The modacrylic fibers A contain the infrared absorber inside the fibers. The presence of the infrared absorber inside the modacrylic fibers does not interfere with the soft texture of the modacrylic fibers compared with the case in which the infrared absorber is adhered to the fiber surface, and thus the texture is better. Furthermore, the infrared absorber is unlikely to be detached from the modacrylic fibers during washing and use, and thus the durability such as washing resistance is high.

From the viewpoint of spinnability, cost, and uniform heat-generating performance, the modacrylic fibers A may be a single component fiber and the infrared absorber may be dispersed throughout the fiber interior.

Infrared Absorber

There is no particular limitation on the infrared absorber, as long as it has an infrared-absorbing effect. For example, the infrared absorber may have an absorption peak in a wavelength region of 750 to 2500 nm. Specific examples thereof include antimony-doped tin oxide, indium tin oxide, niobium-doped tin oxide, phosphorus-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide supported on a titanium oxide substrate, iron-doped titanium oxide, carbon-doped titanium oxide, fluorine-doped titanium oxide, nitrogen-doped titanium oxide, aluminum-doped zinc oxide, and antimony-doped zinc oxide. Indium tin oxide includes indium-doped tin oxide and tin-doped indium oxide. From the viewpoint of improving the infrared absorbency and the heat-generating performance in use in combination with animal hair fibers, the infrared absorber may be a tin oxide-based compound, one or more selected from the group consisting of antimony-doped tin oxide, indium tin oxide, niobium-doped tin oxide, phosphorus-doped tin oxide, fluorine-doped tin oxide, and antimony-doped tin oxide supported on a titanium oxide substrate, one or more selected from the group consisting of antimony-doped tin oxide and antimony-doped tin oxide supported on a titanium oxide substrate, or antimony-doped tin oxide supported on a titanium oxide substrate. Furthermore, the use of the above-mentioned infrared absorbers is preferable because it increases the infrared absorbency and the heat-generating property when they are used in combination with animal hair fibers, and also can make the modacrylic fibers lighter in color. These infrared absorbers may be used alone or in a combination of two or more.

In this specification, the range indicated by “ . . . to . . . ” is the same as the range indicated by “ . . . or more and . . . or less”.

The particle size of the infrared absorber may be 2 μm or less, 1 μm or less, or 0.5 μm or less, from the viewpoint of facilitating dispersion in the acrylic polymer that constitutes the modacrylic fibers. In one or more embodiments of the present invention, the particle size of the infrared absorber can be measured by laser diffraction in the case of a powder, or by laser diffraction or dynamic light scattering in the case of a dispersion (dispersion liquid) dispersed in water or organic solvent.

The modacrylic fibers A may further contain a flame retardant or an auxiliary flame retardant, in addition to the infrared absorber. Examples of the auxiliary flame retardant include an antimony compound. The content of the antimony compound in the modacrylic fibers may be 2 to 30% by weight, or 3 to 20% by weight, with respect to the total weight of the fibers. If the content of the antimony compound in the modacrylic fibers is within the above-mentioned range, the production stability of the spinning process is excellent and the flame retardance is good.

Examples of the antimony compound include antimony trioxide, antimony tetroxide, antimony pentoxide, antimonic acid, sodium antimonate, and other salts of antimonic acid, and antimony oxychloride, which may be used alone or in a combination of two or more. From the viewpoint of the production stability of the spinning process, the antimony compound may be one or more compounds selected from the group consisting of antimony trioxide, antimony tetroxide, and antimony pentoxide.

Furthermore, the modacrylic fibers A may contain various additives such as matting agents, crystal nucleating agents, dispersants, lubricants, stabilizers, fluorescent agents, antioxidants, antistatic agents, and pigments, as necessary, as long as the effects of one or more embodiments of the present invention are not inhibited.

Acrylic Polymer

The modacrylic fibers A may be comprised of an acrylic polymer containing 40 to 70% by weight of acrylonitrile and 30 to 60% by weight of the other components with respect to the total weight of the acrylic polymer. If the content of acrylonitrile in the acrylic polymer is 40 to 70% by weight, the modacrylic fibers have good heat resistance and flame retardance.

There is no particular limitation on the other components, as long as they can be copolymerized with acrylonitrile, but examples thereof include halogen-containing vinyl-based monomer and sulfonic acid group-containing monomer.

Examples of the halogen-containing vinyl-based monomer include halogen-containing vinyl and halogen-containing vinylidene. Examples of the halogen-containing vinyl include vinyl chloride and vinyl bromide, and examples of the halogen-containing vinylidene include vinylidene chloride and vinylidene bromide. These halogen-containing vinyl-based monomers may be used alone or in a combination of two or more. From the viewpoint of heat resistance and flame retardance, the modacrylic fibers may contain 30 to 60% by weight of halogen-containing vinyl-based monomer, as other components, with respect to the total weight of the acrylic polymer.

Examples of the sulfonic acid group-containing monomer include methacrylic sulfonic acid, allyl sulfonic acid, styrenesulfonic acid, 2-acrylamide-2-methylpropanesulfonic acid, and salts thereof. In this case, examples of the salts include, but are not limited to, sodium, potassium, and ammonium salts, such as sodium p-styrenesulfonate. These sulfonic acid group-containing monomers may be used alone or in a combination of two or more. Sulfonic acid group-containing monomer are used as necessary. For example, the content of sulfonic acid group-containing monomers in the acrylic polymer may be 0.5% by weight or more, and, if the content of sulfonic acid group-containing monomers in the acrylic polymer is 3% by weight or less, the production stability of the spinning process is excellent.

The acrylic polymer may be a copolymer obtained by copolymerizing 40 to 70% by weight of acrylonitrile, 30 to 57% by weight of halogen-containing vinyl-based monomer, and 0 to 3% by weight of sulfonic acid group-containing monomer. The acrylic polymer may be a copolymer obtained by copolymerizing 45 to 65% by weight of acrylonitrile, 35 to 52% by weight of halogen-containing vinyl-based monomer, and 0 to 3% by weight of sulfonic acid group-containing monomer. The acrylic polymer may be a copolymer obtained by copolymerizing 45 to 65% by weight of acrylonitrile, 34.5 to 52% by weight of halogen-containing vinyl-based monomer, and 0.5 to 3% by weight of sulfonic acid group-containing monomer.

There is no particular limitation on the single fiber fineness of the modacrylic fibers A, but it may be 1 to 20 dtex, or 1.5 to 15 dtex, from the viewpoint of spinnability, processability, and texture and strength when formed into a woven fabric and/or a knitted fabric. Furthermore, there is no particular limitation on the fiber length of the modacrylic fibers, but it may be 38 to 127 mm, or 38 to 76 mm, from the viewpoint of spinnability and processability. In one or more embodiments of the present invention, the single fiber fineness of the fibers is measured based on JIS L 1015.

There is no particular limitation on the strength of the modacrylic fibers A, but it may be 1.0 to 4.0 cN/dtex, or 1.5 to 3.0 cN/dtex, from the viewpoint of spinnability and processability. Furthermore, there is no particular limitation on the elongation at break of the modacrylic fibers, but it may be 20 to 35%, or 20 to 25%, from the viewpoint of spinnability and processability. In one or more embodiments of the present invention, the strength and the elongation at break of the fibers are measured based on JIS L 1015.

The modacrylic fibers A are produced by wet-spinning a spinning solution in the same way as for general modacrylic fibers, except for the addition of the infrared absorber and the like to the acrylic polymer dissolved in the spinning solution.

Animal Hair Fibers

The heat-generating fabric further contains animal hair fibers, in addition to the modacrylic fibers A containing the infrared absorber. There is no particular limitation on the animal hair fibers, but examples thereof include wool, angora, cashmere, mohair, camel, rabbit, and alpaca.

Heat-Generating Fabric

From the viewpoint of heat-generating performance and durability, the heat-generating fabric may contain 30 to 70% by weight of modacrylic fibers A and 30 to 70% by weight of animal hair fibers with respect to the total weight of the heat-generating fabric. In order to increase the amount of heat generated, that is, in order to lower the heat-shielding rate, the heat-generating fabric may contain 40 to 60% by weight of modacrylic fibers A and 40 to 60% by weight of animal hair fibers with respect to the total weight of the heat-generating fabric.

From the viewpoint of heat-generating performance and durability, it is preferable that the heat-generating fabric contains a first yarn and a second yarn whose fiber composition is different from that of the first yarn, the first yarn contains the modacrylic fibers A containing the infrared absorber, and the second yarn contains the animal hair fibers. In this specification, “different fiber composition” means different types and/or amounts of fibers constituting the yarns.

From the viewpoint of heat-generating performance and texture, the heat-generating fabric may contain the infrared absorber in an amount of 0.5 to 20% by weight, 1 to 15% by weight, or 1.5 to 10% by weight, with respect to the total weight of the heat-generating fabric.

From the viewpoint of improving the heat-generating performance, the first yarn may contain the modacrylic fibers A (i.e., the modacrylic fibers containing the infrared absorber) in an amount of 30% by weight or more, 40% by weight or more, or 50% by weight or more, with respect to the total weight of the first yarn. There is no particular limitation on the upper limit of the content of the modacrylic fibers Ain the first yarn, and the first yarn may be constituted by 100% by weight of modacrylic fibers A.

The first yarn may further contain modacrylic fibers other than the modacrylic fibers A (i.e., the modacrylic fibers containing the infrared absorber), as necessary. The modacrylic fibers other than the modacrylic fibers containing the infrared absorber may be modacrylic fibers containing an antimony compound such as antimony oxide, or modacrylic fibers not containing an antimony compound. Furthermore, other fibers also may be contained. The first yarn may be a spun yarn obtained through spinning, which may be obtained by spinning only modacrylic fibers containing the infrared absorber or by spinning together with other fibers. There is no particular limitation on the other fibers, but examples thereof may include one or at least two selected from the group consisting of cellulose-based fibers, polyester-based fibers, nylon-based fibers, aramid fibers, animal hair fibers, and the like. Furthermore, the first yarn may be a spun yarn or a filament yarn. The yarn may be selected as appropriate according to the purpose. For example, the first yarn can be obtained by spinning a fiber mixture containing the modacrylic fibers containing the infrared absorber, using a known spinning method. Example of the spinning method include, but are not limited to, ring spinning, air spinning, and air jet spinning.

The second yarn may be any yarn whose fiber composition is different from that of the first yarn, and at least contains the animal hair fibers from the viewpoint of realizing good moisture release and improving the heat-retaining properties and flame retardance. Furthermore, as with the first yarn, the second yarn may further contain fibers other than the animal hair fibers, and there is no particular limitation on the additional components in the second yarn. There is no particular limitation on the other fibers, but examples thereof may include one or at least two selected from the group consisting of cellulose-based fibers, polyester-based fibers, nylon-based fibers, aramid fibers, modacrylic fibers, and the like. The second yarn may contain the animal hair fibers in an amount of 50 to 100% by weight, or 80 to 100% by weight, with respect to the total weight of the second yarn. The second yarn may be a spun yarn or a filament yarn. The yarn may be selected as appropriate according to the purpose. The second yarn can be obtained through spinning using a known spinning method. Example of the spinning method include, but are not limited to, ring spinning, air spinning, and air jet spinning.

There is no particular limitation on the thickness of the first yarn, but, for example, from the viewpoint of suitability for clothing, blankets, interior decorations, and the like, the thickness may be 5 to 40, or 10 to 30, in term of English cotton count. Furthermore, the yarn type may be single or twin yarn.

There is no particular limitation on the thickness of the second yarn, but, for example, from the viewpoint of suitability for clothing, blankets, interior decorations, and the like, the thickness may be 10 to 60, or 20 to 40, in term of metric count. Furthermore, the yarn type may be single or twin yarn.

There is no particular limitation on the heat-generating fabric, but examples thereof include woven fabric, knitted fabric, and non-woven fabric. Furthermore, the heat-generating fabric may be a woven fabric obtained by interweaving the first yarn and the second yarn, or a knitted fabric obtained by interknitting the first yarn and the second yarn. There is no particular limitation on the woven fabric structure, and it may be three foundation weaves such as a plain weave, a twill weave, and a satin weave, or derivative weaves using special weaving machines such as Dobby and Jacquard machines. There is no particular limitation on the knitted fabric structure, and it may be any of circular, weft, and warp knitting. The woven fabric may be a grid fabric (woven fabric) using two or more types of yarns as a warp yarn and two or more types of yarns as a weft yarn. In the case of a grid fabric, the first yarn may be used as weft and warp yarns, and the second yarn may be used as the grid yarn for weft and warp yarns. There is no particular limitation on the method for producing the non-woven fabric, and it may be any of thermal bonding, chemical bonding, needle punching, and the like.

There is no particular limitation on a fabric weight of the heat-generating fabric, but, in order to lower the heat-shielding properties, that is, in order to enhance the heat-generating performance, the fabric weight may be 100 g/m² or more, 150 g/m² or more, or 200 g/m² or more. From the viewpoint of excellent handling and texture, the fabric weight of the heat-generating fabric may be 500 g/m² or less, 400 g/m² or less, or 350 g/m² or less.

Infrared Source

There is no particular limitation on the infrared source, and it may be any of all objects including those that emit a large amount of infrared rays, such as sunlight and heating tools (e.g., stoves and bonfires), and those that emit a trace amount of infrared rays, such as the human body. With infrared rays from such an infrared source, the heat-generating fabric can generate and store heat.

Textile Product

In one or more embodiments of the present invention, it is sufficient that the textile product is made of the heat-generating fabric described above, and there is no particular limitation thereon, but examples thereof include clothing, blankets, and interior decorations, from the viewpoint of heat-generating performance. The textile product may be made of only the above-described heat-generating fabric, for example. Furthermore, as necessary, the textile product may further contain other fabrics or fibers.

The textile product can be used as an outer garment when using sunlight as the infrared source, and can be used as an inner garment when using a trace amount of infrared rays emitted from the human body. Also, the textile product can be used as interior decorations such as blankets, curtains, and sofa fabrics when using a heating tool such as a stove or a bonfire. When a blanket or the like is used in combination with a heating tool, the flame retardance is important, and thus the textile product of one or more embodiments of the present invention may be used. When the front face and the back face of the heat-generating fabric have different exposed ratios of the modacrylic fibers containing the infrared absorber, the textile product may be used such that a face with a higher exposed ratio of the modacrylic fibers containing the infrared absorber is set as a face that is irradiated with infrared rays.

EXAMPLES

Hereinafter, one or more embodiments of the present invention will be described in detail by means of examples. However, the invention is not limited to these examples.

First, the measurement method and the evaluation method will be described.

Single Fiber Fineness, Strength, and Elongation at Break of Modacrylic Fibers

They were measured based on JIS L 1015.

Heat-Shielding Property Test of Fabric

The heat-shielding properties were obtained based on JIS L 19512019 “Textiles-Determination of heat-ray shielding performance” as a method for measuring the heat-generating performance when a fabric is irradiated with infrared rays.

The heat-shielding property test was performed under the following conditions.

Measurement environment: 20° C.×65% RH

Light source type: Artificial solar illuminant XC-500EFSS manufactured by SERIC Co. Ltd

Irradiation face: One face of test piece (a face with a higher exposed ratio of a weft yarn)

The heat-shielding rate is a ratio obtained by dividing, by the temperature rise in a heat ray receiver in a blank test, a difference between the temperature rise in the heat ray receiver to which a test piece is attached and the temperature rise in the heat ray receiver in the blank test. The lower the heat-shielding rate, the higher the heat-generating performance, and, the higher the heat-shielding rate, the lower the heat-generating performance.

Modacrylic Fibers: Production Example 1

An acrylic copolymer constituted by 51% by weight of acrylonitrile, 48% by weight of vinylidene chloride, and 1% by weight of sodium p-styrenesulfonate was dissolved in dimethylformamide to a resin concentration of 30% by weight. Then, 5 parts by weight of antimony-doped tin oxide (which may be referred to as ATO) (product name “SN-100P” manufactured by Ishihara Sangyo Kaisha, Ltd.), 10 parts by weight of antimony trioxide (Sb₂O₃, product name “Patx-M” manufactured by Nihon Seiko Co., Ltd.), and 5 parts by weight of titanium oxide (product name “R-22L” manufactured by Sakai Chemical Industry Co., Ltd.) were added to the obtained resin solution with respect to 100 parts by weight of the resin weight, to form a spinning solution.

The obtained spinning solution was extruded using a nozzle with a nozzle hole diameter of 0.08 mm and a number of holes of 300 into 50% by weight of dimethylformamide solution, allowed to be coagulated, washed with water, dried at 120° C., stretched to three times its length, and heated at 145° C. for 5 minutes, and thus modacrylic fibers were obtained. The obtained modacrylic fibers of Production Example 1 had a single fiber fineness of 1.7 dtex, a strength of 2.4 cN/dtex, an elongation at break of 25%, and a cut length of 51 mm. The modacrylic fibers of Production Example 1 contained ATO inside the fibers, and the content of ATO was 4.2% by weight with respect to the total weight of the modacrylic fibers.

The obtained modacrylic fibers were spun through ring spinning. The obtained spun yarn was a twin yarn with an English cotton count of 20.

Modacrylic Fibers: Production Example 2

Modacrylic fibers were obtained in a similar way to that of Production Example 1, except that 5 parts by weight of antimony-doped tin oxide supported on a titanium oxide substrate (which may be referred to as Ti-ATO) (product name “ET521W” manufactured by Ishihara Sangyo Kaisha, Ltd.) and 10 parts by weight of antimony trioxide (Sb₂O₃, product name “Patx-M” manufactured by Nihon Seiko Co., Ltd.) were added to the obtained resin solution with respect to 100 parts by weight of the resin weight, to form a spinning solution. The obtained modacrylic fibers of Production Example 2 had a single fiber fineness of 1.7 dtex, a strength of 2.6 cN/dtex, an elongation at break of 27%, and a cut length of 51 mm. The modacrylic fibers of Production Example 2 contained Ti-ATO inside the fibers, and the content of Ti-ATO was 4.3% by weight with respect to the total weight of the modacrylic fibers.

The obtained modacrylic fibers were spun through ring spinning. The obtained spun yarn was a twin yarn with an English cotton count of 20.

Table 1 below shows the additives used in Production Examples 1 and 2 and the amount of additives added with respect to 100 parts by weight of the acrylic polymer.

TABLE 1 Auxiliary flame Produc- Infrared absorber retardant Other additives tion Parts by Parts by Parts by Example Name weight Name weight Name weight 1 ATO 5 Antimony 10 Titanium 5 trioxide oxide 2 Ti-ATO 5 Antimony 10 — — trioxide

Example 1

A 2/1 twill woven fabric was produced using a wool spun yarn (a twin yarn with a metric count of 34) as a warp yarn and the spun yarn of Production Example 1 as a weft yarn, and fibers on both faces were raised. The number of warp yarn was 48.6/inch, the number of weft yarn was 41/inch, and the fabric weight was 271 g/m². In Example 1, the weft yarn was the first yarn, and the warp yarn was the second yarn. The woven fabric of Example 1 contained 45% by weight of the first yarn and 55% by weight of the second yarn with respect to the total weight of the woven fabric.

The heat-shielding rate (when a face with a weft yarn exposed ratio of 67% was irradiated) of the woven fabric obtained in Example 1 was 34.7%.

Example 2

A woven fabric was produced in a similar way to that of Example 1, except that the spun yarn of Production Example 2 was used as a weft yarn. The fabric weight was 270 g/m².

The heat-shielding rate (when a face with a weft yarn exposed ratio of 67% was irradiated) of the woven fabric obtained in Example 2 was 34.8%.

Comparative Example 1

A2/1 twill woven fabric was produced using the spun yarn of Production Example 2 as a warp yarn and the spun yarn of Production Example 2 as a weft yarn, and fibers on both faces were raised. The number of warp yarn was 48.6/inch, the number of weft yarn was 41/inch, and the fabric weight was 266 g/m².

The heat-shielding rate (when a face with a weft yarn exposed ratio of 67% was irradiated) of the woven fabric obtained in Comparative Example 1 was 40.1%.

Comparative Example 2

A 2/1 twill woven fabric was produced using a wool spun yarn (a twin yarn with a metric count of 34) as a warp yarn and a wool spun yarn (a twin yarn with a metric count of 34) as a weft yarn, and fibers on both faces were raised. The number of warp yarn was 48.6/inch, the number of weft yarn was 41/inch, and the fabric weight was 280 g/m².

The heat-shielding rate (when a face with a weft yarn exposed ratio of 67% was irradiated) of the woven fabric obtained in Comparative Example 2 was 43.9%.

Table 2 below shows a list of the heat-shielding rates of the woven fabrics of Examples 1 and 2 and Comparative Examples 1 and 2. Table 2 also shows the fiber compositions of the first yarn and the second yarn, the weight ratio between the first yarn and the second yarn, the amount of infrared absorber added with respect to the total weight of the fabric, and the fabric weight.

TABLE 2 Amount of infrared Heat- First yarn (weft) Second yarn (warp) absorber added with shielding Amount Amount First yarn/ respect to total Fabric rate of (% by (% by second yarn weight of fabric weight fabric Fiber weight) Fiber weight) (weight ratio) (% by weight) (g/m²) (%) Ex. 1 Modacrylic 100 Wool 100 45/55 1.9 271 34.7 fiber:Production Example 1 Ex. 2 Modacrylic 100 Wool 100 45/55 1.9 270 34.8 fiber:Production Example 2 Com. Modacrylic 100 Modacrylic 100 45/55 4.2 266 40.1 Ex. 1 fiber:Production fiber:Production Example 2 Example 2 Com. Wool 100 Wool 100 45/55 0 280 43.9 Ex. 2

It is clear from Table 2 that the fabrics of the example have a low heat-shielding rate and generate heat. On the other hand, the fabrics of the comparative examples have high heat-shielding properties, and, in particular, the heat-shielding rate of the examples is lower than that of the wools of Comparative Example 2, that is, it is seen that the fabrics of one or more embodiments of the present invention have excellent heat-generating performance.

One or more embodiments of the present invention may include, without limitation, one or more of the following embodiments, for example.

[1] A heat-generating fabric containing an modacrylic fiber A and an animal hair fiber,

wherein the modacrylic fiber A contains an infrared absorber inside the fiber, in an amount of 1 to 30% by weight with respect to a total weight of the modacrylic fiber, and

the fabric has a heat-shielding rate of less than 40% as measured according to JIS L 1951:2019.

[2] The heat-generating fabric according to [1], containing 0.5 to 20% by weight of the infrared absorber with respect to a total weight of the heat-generating fabric.

[3] The heat-generating fabric according to [1] or [2], wherein the modacrylic fiber A further contains an antimony compound inside the fiber.

[4] The heat-generating fabric according to any one of [1] to [3], wherein the animal hair fiber is wool.

[5] The heat-generating fabric according to any one of [1] to [4], containing 30 to 70% by weight of the modacrylic fiber A and 30 to 70% by weight of the animal hair fiber with respect to a total weight of the heat-generating fabric.

[6] The heat-generating fabric according to any one of [1] to [5], containing a first yarn and a second yarn whose fiber composition is different from that of the first yarn,

wherein the first yarn contains the modacrylic fiber A, and the second yarn contains the animal hair fiber.

[7] The heat-generating fabric according to any one of [1] to [6], wherein the infrared absorber is a tin oxide-based compound.

[8] A textile product containing the heat-generating fabric according to any one of [1] to [7].

Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present disclosure. Accordingly, the scope of the invention should be limited only by the attached claims. 

1. A heat-generating fabric comprising an modacrylic fiber A and an animal hair fiber, wherein: the modacrylic fiber A comprises an acrylic polymer comprising 40 to 70% by weight of acrylonitrile, the modacrylic fiber A comprises an infrared absorber inside the fiber, in an amount of 1 to 30% by weight with respect to a total weight of the modacrylic fiber, and the fabric has a heat-shielding rate of less than 40% as measured according to JIS L 1951:2019.
 2. The heat-generating fabric according to claim 1, comprising 0.5 to 20% by weight of the infrared absorber with respect to a total weight of the heat-generating fabric.
 3. The heat-generating fabric according to claim 1, wherein the modacrylic fiber A further comprises an antimony compound inside the fiber.
 4. The heat-generating fabric according to claim 3, wherein the modacrylic fiber A comprises 2 to 30% by weight of the antimony compound with respect to a total weight of the modacrylic fiber A.
 5. The heat-generating fabric according to claim 3, wherein the antimony compound comprises one or more selected from the group consisting of antimony trioxide, antimony tetroxide, and antimony pentoxide.
 6. The heat-generating fabric according to claim 1, wherein the animal hair fiber is wool.
 7. The heat-generating fabric according to claim 1, comprising 30 to 70% by weight of the modacrylic fiber A and 30 to 70% by weight of the animal hair fiber with respect to a total weight of the heat-generating fabric.
 8. The heat-generating fabric according to claim 1, comprising a first yarn and a second yarn whose fiber composition is different from that of the first yarn, wherein the first yarn comprises the modacrylic fiber A, and the second yarn comprises the animal hair fiber.
 9. The heat-generating fabric according to claim 1, wherein the infrared absorber is a tin oxide-based compound.
 10. The heat-generating fabric according to claim 1, having a fabric weight of 100 to 350 g/m².
 11. A textile product comprising the heat-generating fabric according to claim
 1. 12. The textile product according to claim 11, wherein the heat-generating fabric comprises 0.5 to 20% by weight of the infrared absorber with respect to a total weight of the heat-generating fabric.
 13. The textile product according to claim 11, wherein the modacrylic fiber A further comprises an antimony compound inside the fiber.
 14. The textile product according to claim 13, wherein the modacrylic fiber A comprises 2 to 30% by weight of the antimony compound with respect to a total weight of the modacrylic fiber A.
 15. The textile product according to claim 13, wherein the antimony compound comprises one or more selected from the group consisting of antimony trioxide, antimony tetroxide, and antimony pentoxide.
 16. The textile product according to claim 11, wherein the animal hair fiber is wool.
 17. The textile product according to claim 11, wherein the heat-generating fabric comprises 30 to 70% by weight of the modacrylic fiber A and 30 to 70% by weight of the animal hair fiber with respect to a total weight of the heat-generating fabric.
 18. The textile product according to claim 11, wherein the heat-generating fabric comprises a first yarn and a second yarn whose fiber composition is different from that of the first yarn, and wherein the first yarn comprises the modacrylic fiber A, and the second yarn comprises the animal hair fiber.
 19. The textile product according to claim 11, wherein the infrared absorber is a tin oxide-based compound.
 20. The textile product according to claim 11, wherein the heat-generating fabric has a fabric weight of 100 to 350 g/m². 